Robot obstacle detection system

Abstract

A robot obstacle detection system including a robot housing which navigates with respect to a surface and a sensor subsystem having a defined relationship with respect to the housing and aimed at the surface for detecting the surface. The sensor subsystem includes an optical emitter which emits a directed beam having a defined field of emission and a photon detector having a defined field of view which intersects the field of emission of the emitter at a region. A circuit in communication with a detector redirects the robot when the surface does not occupy the region to avoid obstacles. A similar system is employed to detect walls.

Description

PRIORITY CLAIM[0001]This application is a continuation-in-part application of patent application Ser. No. 09 / 768,773 filed Jan. 24, 2001 now U.S. Pat. No. 6,594,844 which claims priority from Provisional Application Ser. No. 60 / 177,703 filed Jan. 24, 2000. This application is also related to patent application Ser. No. 10 / 167,851 and International Publication No. WO 02 / 101477 A2 both incorporated herein by this reference.FIELD OF THE INVENTION[0002]This invention relates to an obstacle detection system for an autonomous robot, such as an autonomous cleaning robot.BACKGROUND OF THE INVENTION[0003]There is a long felt need for autonomous robotic cleaning devices for dusting, mopping, vacuuming, and sweeping operations. Although technology exists for complex robots which can, to some extent, “see” and “feel” their surroundings, the complexity, expense and power requirements associated with these types of robotic subsystems render them unsuitable for the consumer marketplace.[0004]The a...

AI Technical Summary

Benefits of technology

[0006]It is therefore an object of this invention to provide a robot obstacle detection system which is simple in design, low cost, accurate, easy to implement, and easy to calibrate.

[0007]It is a further object of this invention to provide such a robot detection system which prevents an autonomous cleaning robot from driving off a stair or obstacle which is too high.

[0008]It is a further object of this invention to provide a robotic wall detection system which is low cost, accurate, easy to implement and easy to calibrate.

[0009]It is a further object of this invention to provide such a robot wall detection system which effects smoother robot operation in the wall following mode.

[0012]The invention results from the realization that a low cost, accurate, and easy to implement system for either preventing an autonomous cleaning robot from driving off a stair or over an obstacle which is too high or too low and / or for more smoothly causing the robot to follow a wall for more thorough cleaning can be effected by intersecting the field of view of a detector with the field of emission of a directed beam at a predetermined region and then detecting whether the floor or wall occupies that region. If the floor does not occupy the predefined region, a stair or some other obstacle is present and the robot is directed away accordingly. If a wall occupies the region, the robot is first turned away from the wall and then turned back towards the wall at decreasing radiuses of curvature until the wall once again occupies the region of intersection to effect smoother robot operation in the wall following mode.

Problems solved by technology

Although technology exists for complex robots which can, to some extent, “see” and “feel” their surroundings, the complexity, expense and power requirements associated with these types of robotic subsystems render them unsuitable for the consumer marketplace.

Unfortunately, however, presently available sensor subsystems such as sonar sensors for detecting obstacles on or in the floor or for detecting the wall in order to enter the wall following mode (or to avoid bumping into the wall) are either too complex or too expensive of both.

Tactile sensors are inefficient.

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